toxic plants

Plan Now for Fall Crocus & Colchichum

I was thrilled to see the first evidence of Crocus foliage pushing their way out of the frozen soil today. Crocus is the earliest bulb (corm, really) to flower in the Mary Snoddy garden, usually in February. At times they are frosted by ice or snow, which doesn’t seem to dampen their cheerful demeanor one bit.

As much as I enjoy these harbingers of spring, I prefer the Crocus that flower in October and November. You will notice that I did not say “Fall-flowering Crocus” or “Autumn Crocus.” There is a good reason why. There are two different flowers which bloom at the same time and look very similar to the unpracticed eye. One produces saffron threads, a culinary delight. The other can kill you if you eat any part of it. Seriously.

Fall-flowering Crocus, Crocus sativus, pronounced CROW-cuss suh-TAI-vuss, is also known as Saffron Crocus. It is grown for saffron spice, as noted above, but the orange-red stigmas are also used for dye. They will stain fingers and clothing. This plant sends up narrow, grass-like foliage before the flowers appear. Plants are small, usually reaching about six inches when they are in flower. C. sativus is cold-hardy in zones 5-8. They prefer a neutral to slightly alkaline soil in full sun. They are occasionally damaged by voles or rabbits.

Autumn Crocus is Colchicum autumnale, pronounced COAL-chik-um aw-tum-NAH-lay. It is taller (eight to ten inches) and its blooms are larger than C. sativus. It appears as a naked bloom, with no foliage at the time of flowering. Weak foliage appears in spring. It is more cold-tolerant (zones 4-10) than C. sativus, will tolerate a wider range of pH, and will withstand a bit more shade. The large pink or purple flowers look fantastic when they appear above a short groundcover like dwarf mondo grass, which also helps support the weak stems. All parts of the plant are highly toxic to people and pets. Deer and rabbits will not touch them.

Tiny C. sativus is planted 2-3 inches deep. Larger C. autumnale is planted 4-6 inches deep. Both these corms are small and flat, and look best when planted in groups or drifts. They will naturalize when planted in the lawn. Pollinators are attracted to the flowers.

Weed Rant: Horse Nettle

It is time for another weed rant. Horse nettle, Solanum carolinense (pronounced so-LAN-num kair-oh-lin-EN-say), is number two on my list of Weeds From Hades. (Number one is mulberryweed. Click HERE to review A Terrible, Horrible, No Good Weed.) Horse nettle has two, and only two, positive attributes. It is southeastern native, and bumblebees love the pale lavender flowers. If I was feeling generous toward this plant demon (I’m not), I could add that wild turkey, quail and a few songbirds enjoy the berries. The berries and all other parts of the plant are seriously toxic to humans, pets, and livestock.

Horse nettle is found in more than half of the USA. It is a tap-rooted perennial that will grow in any type of soil and any pH. It grows along sunny roadsides, in open fields, and in cultivated gardens. I thought that tilling the soil in my orchard would vanquish this foe, but instead the tilling process broke the root and its fleshy rhizomes into pieces, all of which returned with a vengeance. I do not use herbicides in areas where food is grown, so the only method of removal is digging and pulling. The razor-sharp prickles penetrate thin garden gloves, so I have added a pair of cheap pliers to my bucket of garden tools. I grasp the base of the plant with the pliers and lift gently, while using a tool in the other hand to loosen and lift the rhizomes that radiate off the tap root. It is a slow process, better done after a rain has softened the soil. [Side note: Prickles are modified plant hairs, spines are modified leaves, and thorns are modified stems. Roses have prickles, not thorns. Best not to mention this to poetry-writing friends.] Even if the prickles do not stab you, the star-shaped hairs cause misery when they brush against an unprotected ankle.

Young horse nettle leaves resemble tomato. Stems zig-zag and become woody with age. Plants may be 30 inches or more in height, but tend to sprawl rather than growing upright. They flower from spring all the way into fall. The fruits are round green marbles containing several seeds each. In late fall, the green fruits turn yellow and can be mistaken for a tiny tomato. Fully ripe berries wrinkle a bit. If you have children or grandchildren, please educate them about this plant. Ripe, yellow fruits are even more toxic than the green ones. Consuming them can lead to coma or death. Not only does horse nettle stab the careless gardener, it also plays host to tobacco hornworms and Colorado potato beetles.

If herbicide is your chosen method for eradication, check the label to be certain it is listed. Horse nettle is resistant to some herbicides (2,4D for instance) and repeated mowing has no effect.

Other common names for horse nettle include bull nettle, devil’s tomato, or apple of Sodom. The name of those in the Mary Snoddy garden is not fit for print.

Cold Gold - Winter Aconite

Recent rains and gusty winds brought down the last colorful autumn leaves. It will be a few weeks before crocus, hellebores, mahonias and edgeworthias start blooming. In browsing for new garden additions to brighten the winter scene, I ran across Winter Aconite, sometimes called Buttercup.

Eranthus hyemalis, pronounced er-AN-thiss hy-eh-MAY-liss, enjoy similar light conditions as Hellebores: full sun during bloom period, partial shade otherwise. This makes them an ideal candidate to plant under deciduous trees. They enjoy regular moisture but will tolerate less during dormancy. Golden yellow Winter Aconites bloom early, even before crocus.

The plants grow from tubers which should be planted rather deep (5 inches in good soil, a little shallower in heavy clay) so they are not damaged by cold. Soak the tubers overnight before planting to give them a good start. Winter Aconites are petite plants and should be planted close together in tight groups rather than spaced apart. They enjoy a rich soil and will survive in zones 4-9.

Plants can be propagated by division. Happy plants grown in fertile soil with plentiful moisture may reseed, sometimes heavily. They can be planted in the lawn as well as in flower beds, since the post-bloom foliage will wither and die before it’s time to mow grass in the spring. This is one of the few plants unaffected by the toxic substance, juglone, produced by black walnut trees.

Regretfully, I’ll need to forgo this one. Winter Aconites are extremely toxic to humans and pets. Eating the bloom, leaves or bulbs results in nausea, disrupts heart rhythms and can be deadly.

The photo is of a plant in a local botanical garden.

Winter Aconite at Hatcher Garden and Woodland Preserve, Spartanburg, SC. Anonymous photographer.

Winter Aconite at Hatcher Garden and Woodland Preserve, Spartanburg, SC. Anonymous photographer.

Castor Beans

If you love the look of tropical plants but don’t have the climate for them, consider growing Castor Bean, a plant with dinner-plate sized leaves.

Ricinis communis has gained negative attention in the past because the seeds can be processed (don’t ask me how) to produce the deadly poison Ricin. The word ricinis is Latin for tick, and that is exactly what the seeds look like – big, overblown dog ticks. Seeds should be started where you want the plants to grow, since they do not transplant easily.  I allow them to mature and drop seeds in the Mary Snoddy garden, and love that they pop up in random places.

They are heat lovers and grow rapidly to 8 feet or more. Thomas Jefferson grew a prize specimen that topped 22 feet. Castor bean blooms and seeds are not particularly decorative. Grow them for their bold, deeply palmate leaves. Some cultivars have an attractive red tint to the foliage. The stems resemble bamboo a bit.  They are annuals in my Zone 7 garden, but can be perennial in warmer zones.

The leaves and seeds are toxic if ingested. The plants contain two separate poisons. The most lethal of these poisons is contained in the seed. Two seeds, chewed and swallowed, can kill a person. This is the same plant whose seeds can be processed to remove the ricin (again, don’t ask me how) to produce the nasty-tasting Castor Oil that was given to ailing children many years ago. I think this archaic practice has fallen off the radar. If you remember it from your childhood and wonder about your parents’ wisdom in dosing you with it, well, consider that maybe you weren’t their favorite kid.

Please don’t grow these if you have young children or pets that like to chew on plants. Several years ago, I was experiencing devastation from deer that were visiting my vegetable garden every night. I planted a moat of Castor Beans as a protective hedge, hoping to repel the deer or at least make them sick enough to leave my garden alone. The voracious herd at New Hope Farm ate the leaves off the plants but didn’t touch the seeds. I have since installed an electric fence to protect the food garden. Folklore says that they repel voles and moles, but my personal experience does not support that theory.

Castor Beans die at the first freeze. The large plants require a mattock and labor to remove the dead stems and roots, but I think it is well worth the effort.